The invention relates to a wind power generator with internal cooling circuit and having a stator that is implemented in sheet metal and comprises a winding system which forms winding heads at the end faces of the stator, wherein the stator is enclosed by a cooling jacket at least in the region of its laminated core, wherein permanent magnets of a rotor are disposed on a magnet wheel jacket embodied as a hollow shaft.
Wind power generators, like other dynamoelectric machines, require cooling of their active parts. In this case the interior space of the wind power generator in particular, i.e. the electrical domain, is at risk from foreign bodies or aggressive media which, inter alia, attack the insulation or have an adverse impact on electrical breakdown strength. This leads to detrimental effects on operation or to the failure of the wind power generator. For this reason it is normal practice in the case of dynamoelectric machines deployed in an environment of said kind to provide a closed internal cooling circuit which if necessary is recooled by means of external coolers.
DE 199 19 040 C2 discloses a synchronous machine having salient pole rotors or non-salient pole rotors for large-scale wind energy installations, in particular in the offshore sector. Said machine has a stator and a rotor, with stator and rotor each having cooling ducts which are arranged as part of a cooling circuit for a cooling medium for cooling stator and rotor. In this case the stator ducts are embodied as recesses in the stator with a ridge delimiting the stator ducts at the outer circumference of the stator and cooling ducts for a further cooling medium in a stator housing being routed helically and in multiple channels around the stator housing. In this way the cooling medium absorbs heat from the rotor in the region of the rotor ducts and discharges said heat to the stator in the region of the stator ducts.
DE 101 07 298 C1 discloses an enclosed surface-cooled electrical machine having a closed internal cooling medium circuit over the rotor body. In this solution cooling medium channels are present in the rotor on different pitch circles of the rotor body cross-section for different flow directions.